LEUKOCYTE CHANGES AND INTERFERON-PRODUCTION IN CALVES INJECTED WITH HYDROCORTISONE AND INFECTED WITH INFECTIOUS BOVINE-RHINOTRACHEITIS VIRUS

  • 1 January 1979
    • journal article
    • research article
    • Vol. 40  (2) , 238-240
Abstract
Correlations between leukocyte counts and serum interferon titers were determined in calves given hydrocortisone (HC) and infectious bovine rhinotracheitis (IBR) virus. Calves were injected with 1 mg or 3 mg of HC/kg of body wt every 8 h for a total of 9 injections each. Control calves were given placebo injections. Viral inoculation was given i.v. 10 h after the 1st dose of HC or placebo was given. By the time of viral inoculation, all calves injected with HC had developed neutrophilia, and the calves injected with 3 mg of HC developed leukocytosis, lymphopenia and eosinopenia; total leukocyte counts in calves injected with 1 mg of HC were increased, but not as much as in other HC-treated calves. Leukocyte counts in calves given placebo remained essentially unchanged before viral inoculation. At 1 day after IBR virus was inoculated, the number of circulating lymphocytes in HC-treated calves and control calves was decreased by more than 50%, on the average, of the counts taken before the HC injections or inoculation of virus. A significant negative correlation existed between the numbers of circulating lymphocytes and serum interferon titers at 1, 2 and 3 days after inoculation with IBR virus. The interferon response of calves undergoing lymphocyte suppression due to HC was not impaired, but was enhanced.